JP2002161882A - Gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce level of a hammering noise of a discharge valve generated when a pressure is quickly decreased by alternating a cylinder chamber communicated with a discharge hole and prevent a damage of the valve. SOLUTION: A cross section shape of a cylinder chamber 1a is made to an elliptic shape tilted to the suction hole 7 side. A compressibility of a compression chamber 6 from the time when it leaves from the suction hole 7 until it arrives at a discharge hole 8 is enhanced and a pressure of the compression chamber 6 when it arrives at the discharge hole 8 is raised. Thereby, a pressure difference with a preceding compression chamber finishing a discharge is made less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary vane type gas compressor used for GHP and the like.

[0002]

2. Description of the Related Art A rotary vane type gas compressor is shown in FIG.
As shown in FIG. 1, a rotor 2 rotatably provided in a cylinder chamber 1a of a cylinder block 1 and a vane groove 3 formed in the rotor 2 in a radially slidable manner so as to slide freely into and out of a tip 4a. Is the inner peripheral surface 1b of the cylinder block 1.
In addition, both side surfaces are inner wall surfaces 21a, 22a of side blocks.
(See FIG. 2); a compression chamber 6 formed by dividing the cylinder chamber 1a by the vane 4;
6, and open from the short circular arc portion 1c in the cylinder chamber 1a to the front side in the direction in which the rotor 2 rotates and travels to communicate the cylinder chamber 1a with the discharge chamber 10 (see FIG. 2). A gas (refrigerant gas) compressed from the compression chamber 6 to the discharge chamber 10 is passed through the discharge hole 8 to be interposed between the discharge hole 8 and the discharge chamber 10, and the cylinder chamber 1a is moved from the discharge chamber 10 to the cylinder chamber 1a. A discharge valve 9 of a leaf valve type that shuts off the backflow of gas to the suction chamber 14. Is compressed in the compression chamber 6, and the compressed gas is discharged to the discharge chamber 10 through the discharge hole 8 and the discharge valve 9.

[0003] The cross-sectional shape of the cylinder chamber 1a is substantially elliptical, in which a short diameter passing through the center of the short diameter arc portion 1c is orthogonal to a long diameter of the longest radius, and is symmetric with respect to the long diameter.

The compression stroke of the compression chamber 6 (the compression chamber 6 and the suction hole 7
In the process of compressing the gas trapped in the compression chamber 6 and discharging the compressed gas into the discharge chamber 10), the volume in the compression chamber 6 decreases and the gas pressure gradually increases with the rotation of the rotor 2. However, when this pressure becomes higher than the pressure in the discharge chamber 10, the leaf-shaped valve element 9a of the discharge valve 9 separates from the valve seat 9b and bends toward the valve support 9c, so that the discharge valve 9 is kept open. Thus, the compressed gas in the compression chamber 6 is discharged to the discharge chamber 10 via the discharge hole 8. The compression chamber 6
The vane 4 on the rear side (in the rotor rotation direction) approaches the discharge hole 8, and the vane 4 and the short-diameter arc portion 1c of the cylinder chamber 1a
The compression pressure becomes maximum as the compression space of the compression chamber 6 between the pressure and the pressure decreases.

When the leading vane 4 passes through the discharge hole 8 before the discharge from the compression chamber starts, the next compression chamber 6 starts to communicate with the discharge hole 8. At this point, as shown in “Conventional” of FIG. 3, the next compression chamber 6 is in the early stage of the compression stroke,
Since the gas compression is not performed so much, the pressure Pia is lower than the pressure in the discharge chamber 10, the discharge valve 9 is closed, and the backflow is prevented. When the pressure in the compression chamber 6 is higher than the pressure in the discharge chamber 10 and becomes equal to or higher than Ps, the discharge valve 9 is opened to perform discharge.

In the case of a conventionally manufactured rotary vane type gas compressor having a cylinder chamber cross-sectional shape of approximately elliptical and five vanes, the volume of the compression chamber immediately before the compression chamber 6 communicates with the discharge hole 8 is equal to the suction capacity. Approximately 75% of the maximum volume of the compression chamber when the volume is maximized, away from the hole 7 and trapping the gas,
When simply calculated from the relationship between the volume of the trapped gas and the pressure, the pressure Pia of the compression chamber immediately before the compression chamber 6 communicates with the discharge hole 8 rises only about 1.5 times the pressure at the end of the suction. You will not. Further, the pressure Pd of the compression chamber when the compression of the compression chamber 6 is advanced to discharge to the discharge hole 8 is about 5 times or more the pressure Ps at the time of finishing the suction, and the pressure at the time of discharge of the compression chamber 6 The difference between Pd and the pressure Pia of the compression chamber immediately before the compression chamber communicates with the discharge hole is quite large.

Therefore, when the discharge valve 9 is closed to prevent backflow, the valve element 9a bent toward the valve support 9c collides violently with the valve seat 9b and is adsorbed. This collision sound becomes noise and propagates outside the gas compressor. In addition, the leaf-shaped valve 9a may be broken or broken by the collision.

[0008]

SUMMARY OF THE INVENTION The present invention suppresses a sudden change in pressure when a compression chamber communicating with a discharge hole is changed, reduces the noise level generated by a leaf-shaped valve element, and reduces the noise level of the valve element. An object of the present invention is to provide a gas compressor which can prevent damage, and further does not reduce pressure when a compression chamber communicating with a discharge hole is replaced, and does not require a discharge valve.

[0009]

In order to solve the above-mentioned problems, in a gas compressor according to the present invention, a cylinder chamber having an oblong cross section formed in a cylinder block with front and rear portions closed by side blocks. A rotor in the cylinder chamber, which rotates while sliding on both sides on the inner wall surface of the side block, a vane groove formed substantially radially in the rotor, and a slidably protruding and retractable slide in and out of the vane groove. do it,
A vane having a tip slidably in contact with the inner peripheral surface of the cylinder block and both side surfaces sliding on the inner wall surface of the side block, a compression chamber formed by dividing the cylinder chamber by the vane, and a short-diameter arc in the cylinder chamber The suction hole is opened slightly to the forward direction of the rotor than the portion and communicates with the cylinder chamber and the suction chamber, and the cylinder chamber and the discharge chamber are opened slightly in the forward direction of the rotor beyond the short-diameter circular arc portion. A discharge hole to be communicated with, and a leaf valve interposed between the discharge hole and the discharge chamber to allow the gas compressed from the compression chamber to the discharge chamber to pass therethrough and to block a backflow of the gas from the discharge chamber to the cylinder chamber. A discharge valve of the type, increasing or decreasing the volume of the compression chamber with the rotation of the rotor, sucking gas in the suction chamber from the suction hole into the compression chamber, compressing the gas in the compression chamber, To the discharge chamber In the gas compressor for discharging the compressed gas, the cross-sectional shape of the cylinder chamber, the major axis is so forms an inclined elliptical shape to the suction hole side.

The present invention also provides a cylinder chamber having an oblong cross section formed in a cylinder block which is closed in the front and rear by a side block; , A vane groove formed substantially radially in the rotor, and slidably protruding and retracting in the vane groove, with the tip on the inner peripheral surface of the cylinder block and the side surfaces on both sides. A vane that slides on the inner wall surface of the block, a compression chamber formed by dividing the cylinder chamber by the vane, and a cylinder chamber that opens slightly forward in the rotor traveling direction from the short-diameter arc portion in the cylinder chamber. A suction hole that communicates with the suction chamber and a suction hole that opens slightly forward in the rotor traveling direction than the short-arc portion and communicates the cylinder chamber and the discharge chamber. By increasing or decreasing the volume of the compression chamber with the rotation of the gas, the gas in the suction chamber is sucked into the compression chamber from the suction hole, the gas is compressed in the compression chamber, and the compressed gas is discharged from the discharge hole to the discharge chamber. In the gas compressor, the cross-sectional shape of the cylinder chamber is an elliptical shape whose major axis is inclined toward the suction hole, and the elliptical shape satisfies the following [Equation 2]. Where θ is the angle from the reference line in the direction of rotation of the rotor, R is the radius from the center of the rotor at the angle θ, A is the difference between the major axis and minor axis, 2u is the angle formed by the minor arc, and RO is the minor angle. The radius of the circular arc portion, w is an angle of less than 90 ° between the reference line and the major axis, and n1 and n2 are arbitrary orders. The angle w between the reference line and the major axis is 7
When an oblong cylinder chamber having a large inclination and reduced to about 0 ° is used, the pressure change when the compression chamber is replaced is significantly reduced.

[0011]

(Equation 2)

In the compression chamber which has completed the suction stroke, the volume of the compression chamber becomes maximum at an early timing of rotor rotation before the vane preceding the compression chamber reaches the discharge hole, and the vane preceding the compression chamber approaches the discharge hole. When the preceding vane reaches the discharge hole, the compression of the compression chamber is more advanced than that of the conventional elliptical gas compressor, and the pressure difference from the pressure of the preceding compression chamber. Is reduced.

Further, according to the present invention, the volume Vmax of the compression chamber immediately after the end of the suction, the suction pressure Ps, the volume Vi of the compression chamber immediately before the communication with the discharge hole, and the discharge pressure Pd are obtained.

(Vmax / Vi) ^k > Pd / Ps

In order to satisfy the condition (1), the radius R
O, the angle w formed by the reference line and the major axis and the degree n1, with respect to the angle 2u formed by the minor arc portion and the difference A between the major and minor axes,
n2, the suction hole angle position, and the discharge hole angle position are determined. Here, k is a specific heat ratio of the gas to be compressed.

In the case of a refrigerant gas used in an ordinary refrigerator, the specific heat ratio k is about 1.33.

In order to satisfy this condition, the angle w between the reference line and the major axis and the orders n1 and n2, the angle position of the suction hole,
When the discharge hole angular position is determined, the pressure Pi of the compression chamber immediately before communicating with the discharge hole becomes larger than the pressure Pd of the discharge chamber,
The pressure at the time when the vane preceding the compression chamber reaches the discharge hole and the compression chamber is replaced hardly drops, so that backflow does not occur and the use of a discharge valve is not required.

In this type of gas compressor, it has been confirmed that Pd / Ps is slightly smaller than 6 in a normal operation state. As a shape satisfying the condition, for example, w = 70
°, u = 3 °, n1 = 2, n2 = 4 to adjust the positions of the inlet and outlet,

Vmax / Vi = 4/1

(Vmax / Vi) ^k = (4/1)
^{Since 1.33} ≒ 6.32, the discharge valve can be dispensed with even in the normal operation state.

[0021]

Embodiments of the present invention will be described below.
This will be described with reference to FIGS.

FIG. 1 shows a cylinder block 1 of a gas compressor.
FIG. 2 is a longitudinal sectional view of the gas compressor of FIG. 1, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted.

The cylinder chamber 1a of the cylinder block 1 shown in FIG. 1 is used for a five-vane gas compressor (see FIG. 4), and has short diameters OR arranged at 180 ° intervals.
The vicinity of C is a short-diameter arc portion 1c, and the short-diameter arc portion 1c is in sliding contact with the rotor 2, and the other inner peripheral surface 1b is in sliding contact with the tips of five vanes (not shown). The cross-sectional shape of the cylinder chamber 1a is an elliptical shape in which the major axis O-RA is inclined toward the suction hole 7 side.

The oval cross section of the cylinder chamber 1a is set as follows in this embodiment.
In other words, a line connecting the center O of the short-diameter arc portion 1c and the center portion RC of the short-diameter arc portion 1c is defined as the reference line XX, and the rotor 2
The distance (radius) R from the center O to the inner peripheral surface 1b at the position advanced by the angle θ in the rotation direction C is set as shown in [Equation 3].

[0025]

(Equation 3)

Where 2u is the angle formed by the short-diameter arc portion 1c, w is the angle formed between the reference line XX and the long-diameter O-RA, A
Is the difference between the major axis and the minor axis, and n1 and n2 are arbitrary orders.

In FIG. 2, 2a is a rotor shaft integral with the rotor 2, 11 is a lubricating oil reservoir provided at the bottom in the discharge chamber 10, and 12 and 12 are the rotor shaft 2
a is a suction chamber communicating with the suction hole 7; 21 is a front side which is in close contact with the front surface of the cylinder block 1 and closes one side of the cylinder chamber 1a with an inner wall surface 21a. A block 22 is a rear side block that is in close contact with the rear surface of the cylinder block 1 and closes the other side surface of the cylinder chamber 1a with an inner wall surface 22a.
Is a suction port for sucking gas from the outside of the gas compressor into the suction chamber 14, 26 is a compressed gas passage from the discharge hole 8 to the discharge chamber 10, and 27 is attached to an outlet of the compressed gas passage 26. The oil separator 28 for collecting lubricating oil in the compressed gas is a discharge port for discharging the compressed gas in the discharge chamber 10 to the outside of the gas compressor.

Hereinafter, the operation of the gas compressor of this embodiment will be described with reference to FIG.

When the rotor shafts 2a, 2a are rotatably driven by the bearings 12, 12, the compression chamber 6
However, while rotating around the rotor axis, the volume is increased or decreased, and the gas in the suction chamber 14 is sucked from the suction hole 7, compressed and discharged from the discharge hole 8, and the compressed gas is discharged to the discharge chamber. Is the same as a conventional gas compressor.

The vane 4 trailing into the compression chamber 6 is
When the gas passes through the suction hole 7 with the rotation of, the compression chamber 6 sucks gas from the suction chamber 14. During this time, the pressure in the compression chamber 6 is the pressure in the suction chamber 14.

After the vane 4 closes the communication with the suction hole 7, the timing is very short before the vane 4-1 preceding the compression chamber 6 of FIG. Immediately after the communication is cut off, the compression chamber volume (the hatched portion in FIG. 1) reaches the maximum Vmax. The compression of the gas in the compression chamber starts due to the reduction in the volume of the compression chamber 6 following the rotation of the rotor 2. The cross-sectional shape of the cylinder chamber 1a has a long diameter OR
Since A has an oblong shape inclined toward the suction hole 7, the volume of the compression chamber when the preceding vane 4-21 reaches the discharge hole 8 changes from Vmax to Vi (the hatched portion in FIG. 1). And decrease rapidly. Accordingly, the compression speed is significantly higher than that of the conventional gas compressor, and the compression chamber pressure Pi when the preceding vane 4-21 reaches the discharge hole 8 becomes the discharge start pressure Pd (≒).
(Pressure of the discharge chamber 10) (curve of invention 1 in FIG. 3). Therefore, there is no large pressure difference between the pressure Pmax of the compression chamber, which previously discharged the compressed gas to the discharge hole 8, and the valve body 9a of the discharge valve 9 does not suddenly collide with the valve seat 9b. The valve is closed quietly. Accordingly, the noise level generated by the discharge valve 9 is also reduced, and the valve body 9a is prevented from being damaged.

Next, another embodiment of the present invention will be described. In this embodiment, there is no need to provide the discharge valve 9,
It also contributes to improving the reliability of the gas compressor and reducing costs.

The basic shape of this embodiment is the same as that of the above-described embodiment described with reference to FIG. 1, except that the angle w formed by the reference line and the major axis and the orders n1 and n2, The angular position, that is, the angular position at which the trailing vane 4-12 separates the compression chamber 6 from the suction hole 7, and the angular position of the discharge hole 8 are adjusted to set the volume Vmax of the compression chamber 6 immediately after the end of suction. , The suction pressure Ps, the volume Vi of the compression chamber 6 immediately before communicating with the discharge hole 8, and the discharge pressure Pd.

(Vmax / Vi) ^k > Pd / Ps

If the angle w and the orders n1, n2, the angular position of the suction hole 7 and the angular position of the discharge hole 8 are determined so as to satisfy the condition (k is the specific heat ratio of the gas to be compressed), the discharge hole The pressure Pi of the compression chamber 6 immediately before communicating with the pressure chamber 8 becomes larger than the pressure Pd of the discharge chamber 10 (curve of the invention 2 in FIG. 3).
, The pressure when the compression chamber 6 is replaced does not drop, the backflow from the discharge chamber 10 to the compression chamber 6 does not occur, and the need to use the discharge valve 9 (see FIG. 4) is eliminated.

The oblong cross-sectional shape of the present invention in which the major axis of the cylinder chamber is inclined toward the suction hole is not limited to the above-described embodiment.
Various shapes can be employed.

[0037]

As described above in detail, according to the present invention, in the rotary vane type gas compressor, the cross-sectional shape of the cylinder chamber is an elliptical shape whose major axis is inclined to the suction hole side. The pressure difference when the
The noise level generated by the discharge valve can be reduced, and damage to the leaf-shaped valve element of the discharge valve can be prevented.

Further, the angle w and the order n1, n2 formed by the reference line and the major axis, the angle position of the suction hole 7, and the angle position of the discharge hole are adjusted so that the volume of the compression chamber immediately after the end of the suction, the suction When the pressure, the volume of the compression chamber immediately before communication with the discharge hole, and the discharge pressure satisfy predetermined conditions, the pressure of the compression chamber immediately before communication with the discharge hole becomes larger than the pressure of the discharge chamber, and When the preceding vane reaches the discharge hole, pressure fluctuation near the discharge hole due to replacement of the compression chamber during rotation of the rotor is eliminated, and backflow of the compression chamber from the discharge chamber is eliminated. A vane type gas compressor can be realized, which not only eliminates noise caused by the discharge valve, but also contributes to cost reduction and reliability improvement.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a cylinder block of a gas compressor according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the gas compressor of FIG.

FIG. 3 is an explanatory diagram showing a relationship between a vane position and a compression chamber pressure of a five-vane gas compressor.

FIG. 4 is a cross-sectional view showing a conventional gas compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 1a Cylinder chamber 1b Inner peripheral surface 1c Minor arc part 2 Rotor 3 Vane groove 4 Vane 4a Vane tip 6 Compression chamber 7 Suction hole 8 Discharge hole 9 Discharge valve 9a Valve body 9b Valve seat 9c Valve support 10 Discharge chamber Vmax Maximum volume of compression chamber Vi Volume of compression chamber immediately before discharge hole communication

Claims (3)

[Claims] 1. A cylinder chamber having a front and rear side closed by a side block and formed in a cylinder block and having an elliptical cross section. The cylinder chamber is located inside the cylinder chamber and slidingly contacts both side surfaces with an inner wall surface of the side block. A rotating rotor, a vane groove engraved substantially radially on the rotor, and slidably protruding and retracting in the vane groove, with the tip on the inner peripheral surface of the cylinder block and the two side surfaces on the inner wall surface of the side block. And a compression chamber formed by dividing the cylinder chamber by the vane, and a cylinder chamber and a suction chamber which are opened slightly forward in the rotor traveling direction from a short circular arc portion in the cylinder chamber. And a discharge hole that opens slightly forward in the rotor traveling direction than the short circular arc portion to communicate the cylinder chamber and the discharge chamber, and is interposed between the discharge hole and the discharge chamber. A discharge valve of a leaf valve type that allows the compressed gas to pass from the compression chamber to the discharge chamber, and blocks a reverse flow of the gas from the discharge chamber to the cylinder chamber. A gas compressor that increases or decreases the volume, sucks gas in the suction chamber from the suction hole into the compression chamber, compresses the gas in the compression chamber, and discharges compressed gas from the discharge hole to the discharge chamber. A gas compressor characterized in that the cross section of the gas compressor has an oblong shape whose major axis is inclined toward the suction hole. 2. A cylinder chamber having an oblong cross-section formed in a cylinder block, which is closed in the front and rear by a side block, and is provided in the cylinder chamber, with both sides slidingly contacting the inner wall surface of the side block. A rotating rotor, a vane groove engraved substantially radially on the rotor, and slidably protruding and retracting in the vane groove, with the tip on the inner peripheral surface of the cylinder block and the two side surfaces on the inner wall surface of the side block. And a compression chamber formed by dividing the cylinder chamber by the vane, and a cylinder chamber and a suction chamber which are opened slightly forward in the rotor traveling direction from a short circular arc portion in the cylinder chamber. And a discharge hole that opens slightly forward in the rotor traveling direction than the short-diameter arc portion to communicate the cylinder chamber and the discharge chamber, and is compressed by rotation of the rotor. By increasing or decreasing the volume of the chamber, a gas compressor that sucks gas in the suction chamber from the suction hole into the compression chamber, compresses the gas in the compression chamber, and discharges compressed gas from the discharge hole to the discharge chamber. The cross-sectional shape of the cylinder chamber has an elliptical shape whose major axis is inclined toward the suction hole,
A gas compressor characterized in that the shape of the ellipse satisfies the condition of the following [Equation 1], where θ is an angle advanced from a reference line in the rotation direction of the rotor, and R is the center of the rotor at the angle θ. , A is the difference between the major axis and minor axis, 2u is the angle formed by the minor axis arc, RO is the minor arc radius, w is the angle of less than 90 ° between the reference line and the major axis, n1, n2 Is any order. (Equation 1) 3. The volume Vma of the compression chamber immediately after the end of suction.
x, the suction pressure Ps, the volume Vi of the compression chamber immediately before communicating with the discharge hole, and the discharge pressure Pd are (Vmax / Vi) ^k > Pd / P
To satisfy the condition of s, the angle w between the reference line and the major axis and the orders n1 and n2 with respect to the radius RO of the minor arc part, the angle 2u formed by the minor arc part, and the difference A between the major and minor axes are satisfied. 3. The gas compressor according to claim 2, wherein the suction hole angular position and the discharge hole angular position are determined, wherein k is a specific heat ratio of the gas to be compressed. (Vmax / Vi) ^k > Pd / Ps